In social drinkers, performance of certain intellectual activities decreases in relation to increased alcohol use. This research is designed to examine patterns of alcohol use that are associated with dysfunction of the central nervous system (CNS) through population-based studies of neuropsychological, neuroradiographic and neurochemical factors. In addition to cognitive loss, heavy patterns of social drinking influence sober mood. The research has found that depression, while sober, is increased in heavy drinkers. Depression reduces when subjects lower their alcohol consumption. The neuroradiographic correlates of social drinking are being examined.